I'm not super knowledgeable on jq but I found this on the interwebs and I think it will work in your case:
Cut and paste version:
jq -r 'paths(scalars) as $p | [ ( [ $p[] | tostring ] | join(".") ), ( getpath($p) | tojson )] | join(": ")' short.json
Easy(er) to read version:
jq -r '
paths(scalars) as $p
| [ ( [ $p[] | tostring ] | join(".") )
, ( getpath($p) | tojson )
]
| join(": ")
' short.json